GPS bugfix

measurement_main.py

@@ -245,7 +245,7 @@ def monitor_gps(ser, output_file):
     try:
         while ser.is_open:
             nmea_sentence = ser.readline()
-            write_to_file(output_file, nmea_sentence + "\n")
+            write_to_file(output_file, "{}\n".format(nmea_sentence.decode("utf-8") ))
             sleep(1)
     except:
         if not ser.is_open: